/*
* GetsCmd.java --
*
* Copyright (c) 1997 Sun Microsystems, Inc.
*
* See the file "license.terms" for information on usage and
* redistribution of this file, and for a DISCLAIMER OF ALL
* WARRANTIES.
* 
* Included in SQLite3 port to C# for use in testharness only;  2008 Noah B Hart
*
* RCS @(#) $Id: GetsCmd.java,v 1.6 2003/03/08 03:42:44 mdejong Exp $
*
*/
using System.Text;
using System.IO;
namespace tcl.lang
{

  /// <summary> This class implements the built-in "gets" command in Tcl.</summary>

  class GetsCmd : Command
  {

    /// <summary> This procedure is invoked to process the "gets" Tcl command.
    /// See the user documentation for details on what it does.
    /// 
    /// </summary>
    /// <param name="interp">the current interpreter.
    /// </param>
    /// <param name="argv">command arguments.
    /// </param>

    public TCL.CompletionCode cmdProc( Interp interp, TclObject[] argv )
    {

      bool writeToVar = false; // If true write to var passes as arg
      string varName = ""; // The variable to write value to
      Channel chan; // The channel being operated on
      int lineLen;
      TclObject line;

      if ( ( argv.Length < 2 ) || ( argv.Length > 3 ) )
      {
        throw new TclNumArgsException( interp, 1, argv, "channelId ?varName?" );
      }

      if ( argv.Length == 3 )
      {
        writeToVar = true;

        varName = argv[2].ToString();
      }


      chan = TclIO.getChannel( interp, argv[1].ToString() );
      if ( chan == null )
      {

        throw new TclException( interp, "can not find channel named \"" + argv[1].ToString() + "\"" );
      }

      try
      {
        line = TclString.newInstance( new StringBuilder( 64 ) );
        lineLen = chan.read( interp, line, TclIO.READ_LINE, 0 );
        if ( lineLen < 0 )
        {
          // FIXME: Need more specific posix error codes!
          if ( !chan.eof() && !chan.isBlocked( interp ) )
          {

            throw new TclPosixException( interp, TclPosixException.EIO, true, "error reading \"" + argv[1].ToString() + "\"" );
          }
          lineLen = -1;
        }
        if ( writeToVar )
        {
          interp.setVar( varName, line, 0 );
          interp.setResult( lineLen );
        }
        else
        {
          interp.setResult( line );
        }
      }
      catch ( IOException e )
      {
        throw new TclRuntimeError( "GetsCmd.cmdProc() Error: IOException when getting " + chan.ChanName + ": " + e.Message );
      }
      return TCL.CompletionCode.RETURN;
    }
  }
}
